5 SEPTEMBER 1925, Page 17

[To the Editor of the SPECTATOR.]

Sin,—The action of the blacksmith's hammer may be com- pared to that of a pendulum. There is a waste of energy if the hammer is brought to a permanent standstill at the commencement of the rebound. Although he may not realize it, I fancy that this is generally the reason why the smith so frequently causes the hammer to continue rebounding on the anvil while he is considering the nature of his next blow on the iron.—I am, Sir, &c., REG. A. SMITH.

Windermere.